Apparatus foe feeding cutting tools



4 Sheets-Sheet 2 Original Filed Sept. 9, 1944 R #0 T N E V N V l a ll\\\N T T fi l E m m k a a IE 3 Q m MN H. K. BAKER APPARATUS FOR FEEDINGCUTTING TOOLS 3 5 9 1 4 "m p A 4 Sheets-Sheet 3 Original Filed Sept. 9,1944 INVENTOR H. K. BAKER APPARATUS FOR FEEDING CUTTING TOOLS April 14,1953 Original Filed Sept. 9, 1944 4 Sheets-Sheet 4 Low Reissued Apr. 14,1953 UNITED STATES PATENT OFFICE APPARATUS FOR FEEDING CUTTING TOOLSHerbert K. Baker, Detroit, Mich., assignor of twenty-four per cent toHarriett V. Baker and twenty-four per cent to Herbert K. Baker, Jr.

Original No. 2,516,842, dated August 1, 1950, Serial No. 553,432,September 9, 1944. Application for reissue July 28, 1951, Serial No.239,163

10 Claims.

appears in the original patent but forms no part of this matter printedin italics indicates the additions made by reissue.

Matter enclosed in heavy brackets reissue specification;

This invention relates to apparatus for imparting travel motion tomachine carriages, slides or spindle quills for co-operative feedingaction with cutting tools and it has particular reference to mechanismfor actuating in sequence, change in the speed of travel and reversingmotion.

Among the more important objects of the invention are, thesimplification of apparatus with respect to construction andmaintenance; smoothness of action to enhance operating efficiency;accessibility of the pertinent mechanism for adjustment and changes tovary lengths of travel motion and rates of feed in steps of extremelyfine degree.

How the foregoing objects and advantages, together with others whichwill occur to those skilled in the art, are obtained will be clear fromthe following description with accompanying drawings which illustratethe preferred embodiment of the apparatus, and inwhich- Figure l is aview taken from the bottom of the apparatus with the lower portion ofthe housing broken away.

Figure 2 is asectional view of the apparatus as indicated by line IIIIof Figure 1.

Figure 3 is a sectional view of the apparatus as indicated by lineiIII-I-II of Figure 1.

Figure 4 is an enlarged view of a portion of the apparatus.

Figure 5 is a sectional view taken as indicated by line V--V of Figure4.

Referring now to the drawings, the reference numerals l and 2 indicateeach of a pair of worms with extended shafts, having the same hand andlead of thread, which are spaced apart and arranged for revolving inopposite directions. Positioned between these worms and in meshtherewith is worm gear 3, arranged for rotating and reciprocatingmotion, being mounted on stud 3'! with needle bearing 39 (Figures 4 and5). This stud is threaded in and secured to spindle slide or quill 32whereby reciprocating motion of the worm gear is transmitted to thespindle quill.

The reciprocating motion is effected by a worm revolving, causingrotation of the worm gear, while the other worm remains stationary or isrevolved at a slower speed, thus in response to this differential motionthe rotating worm gear is caused to move in a direction lengthwise ofthe worms in mesh therewith at a rate of travel in ratio to thedifference in the speed of these worms. The revolving of worm I whileworm 2 is held stationary or rotated at a lower speed causes Worm gear 3to travel in the direction indicated by arrow 44 (Figure 4). When worm Iis held stationary while worm 2 is rotated, Worm gear 3 is caused totravel in the direction of arrow 45.

As clearly shown in Figure 1, adjacent ends of the two shafts la and 2aof the worms are journalled in housing 8 with ball bearing 46 and somounted to resist longitudinal thrust in both directions. The drive ofworms l and 2 is arranged thru clutch bodies 4 and 5 respectivelymounted on and keyed to shafts lb and 2b of the worms. At one end ofthese clutch bodies for co-operative action therewith are driving clutchcups l2 and I3 respectively in which the ends of the shafts lb and 2bare journaled with needle bearing l4. These clutch cups have hubs 30 and3| respectively and are journalled with ball hearing IS in intermediaterib l6 of housing 8.

Extending from hub 30 of clutch cup l2 and integral therewith is shaftl! on which gears, I9, 20, and 2l are mounted and keyed thereto. Onshaft l8 of clutch cup l3 gear 22 is mounted and keyed. Gear 22 isdriven by and in mesh with gear 20, thus a differential pitch diameterof one in respect to the other of this pair of gears regulates the speedrelation of the two worms when caused to revolve. For furtherco-operative action with the clutch bodies and opposite the drivingclutch cups l2 and I3, stationary clutch cups 6 and 1 respectively aremounted and secured into the intermediate rib 9 of housing 8 andprovided with key ll] interlocking with this intermediate rib to resistrotation. The shafts lb and 2b of the worms extend thru these stationaryclutch cups and journalled with needle hearing I l slidably mounted onthe clutch bodies 4 and 5 are shipper sleeves 23 and 24 respectively forco-operative and selective engagement or disengagement with either thedriving clutch cups or stationary driving clutch cups to in turn revolveor hold stationary the shafts of the worms on which these clutch bodiesare mounted and keyed thereto.

As clearly shown in Figure 5, for the mounting and securing of stud 31to spindle quill 32, a collar 35 is provided thru which one end of thestud extends and is threaded into the spindle quill. Hexagon shoulder 38of the stud is drawn down tight against one end of this collar with itsother end bearing against recess 34 of the spindle quill. This collarrides in slot 36 of the housing for longitudinal travel of the spindlequill with the worm gear. A spacing washer 40 is positioned on the studagainst hexagon shoulder 38 for worm gear 3 to ride in proper alignmentwith the worms in mesh therewith. Re-

taining washer 4I holds the worm gear on the stud to resist thrust, andis secured in place againsta shoulder of the stud by nut 42 which islocked by cotter pin 43.

With respect to the drive of the several shafts, a pulley 28 is mountedand keyed to shaft 2! for engagement with belt 29 extending to a powersource (not shown) such as an electric motor.

Gear 25, mounted and keyed to shaft 21, drives gear 2| which is mountedand keyed on shaft I1 for rotating gears I9 and 20 mounted and keyed onthis shaft also. Gear I9 drives gear 26 which is arranged for drivingspindle 33 mounted in spindle quill 32. See Figures 1, 2, and 3.

Spindle 33 extends out from the spindle quill 32 and has a bored socket41 with keyway 48 Fig1'1re'3) for receiving the shank, of a cuttingtool, a tool holder-or a multiple spindle drill head (not shown).

The spindle quill 32 in its advancement toward work to be performed isrequired to first move at a comparatively fast rate of'travel, commonlyknown in the art as Rapid advance. Then during the performance of thework moves at a slower rate, in conformity with the cutting efficiencyof the tool, called Feed. Upon completion of the work, the spindle quillis caused to reverse its travel direction to its starting position,known as Rapid return.

This Rapid advance, Feed and"Rapid return are sequence phases of areciprocating cycle. In the actuation of the mechanism embodied in thisinvention to obtain, Rapid advance of the spindle quill, first, the wormI is caused to revolve, thus driving worm gear 3, while worm 2 is heldstationary which forces this rotating worm gear to move in a directionindicated by arrow 44 at a comparatively fast rate to compensate for thedifference as to speed of worm I relative to the negative operation ofworm 2. For Feed, at a predetermined point of travel of the spindlequill, worm 2 is caused to revolve also but at a somewhat slower speedthan worm I, as determined by the relative pitch diameters of gears 20and 22, thus changing the rate 'of travel of this spindle quill in ratioto the difference in relative speed of the two worms. Upon completion ofthe Feed phase, worm I is caused to stop and held stationary while worm2 continues to revolve which reverses the direction of travel motion ofthe'worm gear (indicated by arrow 45, Figures 4 and until the spindlequill reaches startin position thereupon worm 2 is also caused to stoprevolving thereby holding worm gear 3 and consequently spindle quill 3'2stationary until again repeating a reciprocating cycle.

To start the spindle quill travel at Rapid advance a double solenoid 50(Figure 2) is provided anda push button switch (not shown) may beoperated and thru wire 54 energize coil 50a of this solenoid, thusshifting forked lever 52 to engage shipper sleeve 23 of clutch body 4with driving clutch cup I2 causing worm I to revolve.

A rod BI, secured to flange 49 of spindle quill 32 and movable therewithcarries-dog 55 adjustable as to position on this rod and held secure byset screw 63.

The rate of travel to "Feed" from Rapid advance is changed at apredetermined point of travel of the spindle quill by dog 55 trippingswitch 56 (Figure 3) and thru wire 66 energizes coil 5Ib of doublesolenoid 5I, thereby actuating forked lever 53 for disengagement ofshipper sleeve 24 of clutch'body 5 from stationary clutch cup 1 toengagement with driving clutch cup I3 4 to revolve worm 2 forcooperation with the revolving worm I.

As shown in Figure 2, a rod 62 is secured to flange 43 of spindle quill32 and on this rod, adjustably mounted are dogs 51 and 53 which are heldto position by set screw 63.

For reversing the travel of the spindle quill to "Rapid return, dog 51trips switch 58 and thru wire 54 energizes coil 50b of double solenoid50 for actuating forked lever 52 to disengage shipper sleeve 23 ofclutch body 4 from driving clutch cup I2 for engagement with stationaryclutch cup 6 to stop revolving and hold stationary worm I while worm 2continues to revolve.

Upon reaching the end of the Rapid return, travel of the spindle quill,dog 53 trips switch 63 and thru wire 65 energizes coil 5Ia of doublesolenoid 5'I thereby actuating the forked lever 53 to shift shippersleeve 24 of clutch body 5 from driving clutch cup I3 to engagement withstationary clutch cup I to stop revolving and hold stationary worm 2. Atthis point both worms are held stationary and the spindle quillunoperative until again actuating the mechanism to. repeat areciprocating cycle.

The clutch assemblies employed in the'structure disclosed herein arepreferably of the multiple disc type with an adjusting ring 61 forregulating pressure against the discs during engagement. In this manner,means are provided for adjusting the pressure of engagement to such anextent that when a specific torque load is exceeded, thru overload asmight occur by breakage of a cutting tool, the clutches will then slipand the mechanism advancing the cutting tool be retarded or stopped,thus preventing serious damage to the apparatus.

Adjustment to a predetermined length of travel of any sequence phaseRapid advance, Feed and Rapid return of a reciprocating cycle isaccomplished by merely loosening set screw 63 of the pertinent dogcausing actuation of the mechanism for the particular sequence phase ofthe reciprocating cycle to be changed and moving this dog on itssupporting rod to position relative to the length of travel desired andsecure thereto by tightening the set screw.

During all phases of an entire reciprocating cycle, the worm gear 3continuously rotates in the same direction, whether driven by one or theother or both worms simultaneously. This action provides a uniformity ofwear to these cooperating members for prolonging their life and smoothoperation with neglible amount of shock to the apparatus duringactuation of the mechanism for changing the rate of travel or reversingdirection of travel of the spindle quill.

Various Feed rates of travel of the spindle quill 32 are obtained bymerely replacing the mating gears 20 and 22 on shafts I1 and I8respectively with another pair of gears of a difierent pitch diameterrelation corresponding to the de sired change in Feed rate. Thisarrangement affords a very fine adjustment, in steps by toothprogression (less in one gear and more in the other), as a single toothchange in differential of each gear only alters minutely the Feed rateof travel due to the longitudinal travel of the worm gear being at arateresulting from the lead of the worm thread multiplied by only halfthe difference between the revolving speeds of the two worms.

In comparison of my improved structure as disclosed herein with another,heretofore, employing for instance thewell known feeding arrangement ofa lead screw and nut, this prior arrangement does not provide as fine afeed adjustment be! cause of the rate of this longitudinal travel mustnecessarily result from the lead of the thread as multiplied by thetotal difference between the revolving speeds of the lead screw and nut,therefore, the steps of feed adjustment necessarily had to be twice ascoarse as provided by the present invention.

Other prior feeding mechanisms employed cams of various types,configured or grooved in relation tothevaried sequence rates of traveland reversing motion desired for the specific cutting tool employed.However, these cam actuated mechanisms required that a new cam be madefor every desired change in Feed" rate or length of travel, and further,a large portion of the apparatus had to be disassembled and reassembledfor the replacement of these cams.

Still other prior feeding arrangements employed hydraulic means forimparting reciprocating movement to the cutting tools. Although finefeeds are obtainable hydraulically, considerable space is required forinstallation of the necessary pump, valves, fluid reservoir and controlswhich is objectionable where compactness is desired. Furthermore in manyinstances when starting up the hydraulic system, the fluid beingcomparatively cold, the feed rate will change as the viscosity of thefluid changes with the heat generated from the pressures involved thruusage. Besides hydraulic systems are sensitive to foreign matter orsludge collecting in the fluid medium over a period of time, thereforethese hydraulic systems usually require frequent servicing to maintainconsistent Feed rates.

From the foregoing it will be apparent the present invention providesimproved means for obtaining extremely fine rates of Feed to meet themost exacting requirements of metal cutting tools in respect to accuracyand finish in the work performed. Finally, other advantages, as will beobserved from this specification, flow from the structure disclosedherein by the use of parts which have maximum strength and life,assembly in a compact arrangement to conserve space and to furtherprovide smoothness of operation with ease of maintenance and adjustment.

What I claim is:

1. In combination, a spindle quill arranged for travel motion adapted tothe feed of a cutting tool, two worms spaced apart in parallel relation,a worm gear operative between the worms and in mesh therewith, a studsecured to the spindle quill for mounting the worm gear in cooperativeassociation with the worms, a spindle rotatably mounted in the spindlequill for rotating a cutting tool, a pair of gears meshed together forrevolving the worms at a relative speed of one greater than the otherand means for driving said pair of gears and said spindlesimultaneously.

2. In combination, a spindle quill arranged for travel motion adapted tothe feed of a cutting tool, a spindle rotatably mounted in the spindlequill for rotating a cutting tool, two worms spaced apart in parallelrelation, a stud secured to the spindle quill, a worm gear rotatablymounted on the stud between the worms and in mesh therewith, a pair ofshafts drivingly connected to said worms, a pair of gears meshedtogether on said shafts for revolving the worms at a relative speed ofone greater than the other, an additional pair of gears drivinglyconnected to the spindle for rotating thespindle, and driving mechanismdrivingly connected to one of said successive pairs of gears beingmounted on one of said shafts.

3. In combination, a frame, two worms journalled in spaced parallelrelation in said frame, a worm gear positioned between the worms and inmesh therewith, said worms having shafts extending from each end of theworm thread, stationary brake cups fixedly secured to said frame, oneend of the shafts being journalled in bearings mounted in said frame toresist lengthwise thrust of the worms in both directions, and the otherend of the shafts journalled in said stationary brake cups, clutchmechanism mounted for cooperative association with said stationary brakecups, and driving clutch cups selectively engageable with said clutchmechanism for revolving the worms.

4. In combination, a frame, a tool-holding slide, means for mounting andguiding said slide for reciprocation relatively to said frame, a pair ofworms rotatably mounted in parallel spaced relationship in said frame, asupport connected to said slide, a worm gear rotatably mounted on saidsupport and disposed between said worms in meshing engagement therewith,a pair of worm driving shafts, mechanism drivingly interconnecting saiddriving shafts for rotation in opposite directions, a tool-holdingspindle rotatably mounted on said slide, means for rotating saidspindle, and clutch devices including a pair of stationary brakeelements secured to said frame, said clutch devices also including meansfor con- -necting each of said worms selectively to its respectivedriving shaft or to its respective stationary element whereby toselectively hold either of said worms stationary while rotating theother or to rotate both of said worms simultaneously so as to providerapid travel or feeding travel of said tool-holding slide.

5. In combination, a frame, a tool-holding slide, means for mounting andguiding said slide for reciprocation relatively to said frame, a pair ofworms rotatably mounted in parallel spaced relationship in said frame, asupport connected to said slide, a worm gear rotatably mounted on saidsupport and disposed between said worms in meshing engagement therewith,a pair of worm driving shafts, mechanism drivingly interconnecting saiddriving shafts for rotation in opposite directions at different relativespeeds, a tool-holding spindle rotatably mounted on said slide anddrivingly connected to one of said worm driving shafts, and clutchdevices including a pair of stationary brake elements secured to saidframe, said clutch devices also including means for connecting each ofsaid worms selectively to its respective driving shaft or to itsrespective stationary element whereby to selectively hold either of saidworms stationary while rotating the other or to rotate both of saidworms simultaneously at different relative speeds so as to provide rapidtravel or feeding travel of said tool- 'holding slide.

6. In combination, a frame, a tool-holding slide, means for mounting andguiding said slide for reciprocation relatively to said frame, a pair ofworms rotatably mounted in parallel spaced relationship in said frame, asupport connected to said slide, a worm gear rotatably mounted on saidsupport and disposed between said worms in meshing engagement therewith,a pair of worm driving shafts, mechanism drivingly interconnecting saiddriving shafts for rotation in opposi-te directions, clutch devicesincluding a pair of stationary brake elements secured to said frame anda pair of rotatable clutch elements drivingly secured to said worms,said clutch devices also including axially shiftable clutch bodiesdrivingly connected to said worm driving shafts and connecting each ofsaid worms selectively to its respective driving shaft or to itsrespective stationary element whereby to selectively hold either of-saidworms stationary while rotating the other or to rotate both of saidworms simultaneously so as to provide rapid travel or feeding travel ofsaid tool-holding slide, magnetically-operated clutch shiftersoperatively connected to said clutch bodies for shifting the same, andmechanism responsive to predetermined travel of said slide forenergizing said clutch shifters.

7. In combination, a spindle carrier arranged for travel motion adaptedto the feed of a cutting tool, two worms spaced apart in parallelrelationship, a worm gear shaft connected to said spindle carrier totravel therewith, a worm gear mounted on said worm gear shaft to operatebetween the worms and in mesh therewith for imparting travel motion tothe spindle carrier, a spindle rotatably mounted on said spindle carrierfor rotating a cutting tool, a pair of gears meshed togather forrevolving the worms at a relative speed of one greater than the other,and mechanism for driving said pair of gears and said spindlesimultaneously.

8. In combination, a spindle carrier arranged for travel motion adaptedto the feed of a cutting tool, two worms spaced apart in parallelrelationship', a Worm gear shaft connected to said spindle carrier totravel therewith, a worm gear mounted on said worm gear shaft to operate'between the worms and in mesh therewith for imparting travel motion tothe spindle carrier, a spindle rotatably mounted on said spindle carrierfor rotating a cutting tool, a pair of gears meshed together forrevolving the worms at a relative speed of one greater than the other,and mechanism for driving said pair of gears and said spindlesimultaneously, and a braking device selectively engageable with one ofsaid worms to halt the same whereby to halt one of said worms sons toimpart a relatively faster speed to the spindle carrier than the speedimparted thereto by the simultaneous revolving of both worms.

' -9.- In combination, a spindle carrier arranged for travel motionadapted .to the feed of a cutting tool, two" worms spaced apart'inparallel relationship, a worm gear shaft connected to said spindlecarrier to'travel therewith, a worm gear mounted on said worm gear shaftto operate between vthe worms and in mesh therewith for imparting travelmotion to the spindle carrier, a spindle rotatably mounted on saidspindle carrier for :rotating a cutting tool, a pair of gears meshedtogether for revolving the worms at a relative speed of one greater thanthe other,'and mechanism for driving said pair of gears and said spindlesimultaneously, and a braking device selectively engagea'ble with eachof said worms to halt the same whereby to halt either one of said wormsso as to impart a relatively faster speed to the spindle carrier thanthe speed imparted thereto by the simultaneous [revolution] resolving ofboth Worms.

10. In combination, a frame, two worms journa'llecl in spaced parallelrelation in said fmme, a worm gear positioned between the worms and inmesh therewith, said worms having support and driving shaft endsextending from the operative lengths of worm thread, and shaft endsiournaled in bearings mounted in said frame to resist lengthwise thrustof the worms in both directions, clutch elements and brake elementsassociated with the'worms operative to halt one of said warms and torotate the other so as to provide relatively rapid reciprocating motionbetween the worm gear and the worms or for rototing both wormssimultaneously at difier'ent speeds to impart a lesser rate 0 1 relativereciproeating travel motion.

HERBERT K. BAKER.

References Cited-in the file of this patent or the original patentUNITED STATES PATENTS Number Name Date 487,775 Richards Dec. 13, 1892750,370 Kammerer Jan. 26, 1904 863,966 Billeter Aug. 20, 1907 1,665,227Smith Apr. 10, 1928 2,179,171 Boho -Nov.- 7, 1939 2,299,635 MacNeil Oct.20, 1942 FOREIGN PATENTS Number Country Date 6,581 Great Britain of 1911490,684 Germany Jan. 31, 1930

